title: Post-competition blood lactate concentrations as indicators of anaerobic energy expenditure during 400-m and 800-m races.
abstract: The relationships between anaerobic glycolysis and the average velocity (v) sustained during running were studied in 17 top level athletes (11 males and 6 females). A blood sample was obtained within 10 min of the completion of major competitions over 400 m, 800 m and 1500 m and the blood lactate concentration [la]b was measured. In both male and female athletes [la]b was related to the relative performance, as expressed as a percentage of the athlete's best v of the season. Over 400 m, r = 0.85 (P less than 0.01) and r = 0.80 (P less than 0.05) in males and females, respectively. Over 800 m, the corresponding values were r = 0.76 (P less than 0.01) and r = 0.91 (P less than 0.01). In male runners [la]b was correlated to v: r = 0.89 (P less than 0.01) and r = 0.71 (P less than 0.02) over 400 m and 800 m, respectively. No relationship to relative performance or v was obtained over 1500 m. Energy expenditure during competition running was estimated in male runners from the [la]b values. This estimate was based mainly on the assumption that a 1 mmol.1-1 increase in [la]b corresponded to the energy produced by the utilization of 3.30 ml.O kg-1. The energy cost of running was estimated, by dividing the estimated total energy expenditure by the race distance, at 0.211 ml.kg-1.min-1 over 800 m and 0.274 ml.kg-1.m-1 over 400 m.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Laboratoire de Physiologie-G.I.P. Exercice, Faculté de Médecine, Lyon-Sud, Oullins, France.
authors.forename: J R
authors.initials: JR
authors.lastname: Lacour
authors.forename: E
authors.initials: E
authors.lastname: Bouvat
authors.forename: J C
authors.initials: JC
authors.lastname: Barthélémy
mesh_terms: D000328:Adult; D000693:Anaerobiosis; D004734:Energy Metabolism; D005260:Female; D006801:Humans; D007773:Lactates / Q000097:blood*; D019344:Lactic Acid; D008297:Male; D010101:Oxygen Consumption; D010710:Phosphates / Q000378:metabolism; D012420:Running
chemical_list: D007773:Lactates; D010710:Phosphates; D019344:Lactic Acid